Method for Constructing a Ballastless Railway Track

ABSTRACT

The present invention relates to a method for the construction of a ballastless railway in which a concrete bedding can be constructed in a correct, well-aligned and finished way, regardless of the location where the concrete bedding must be constructed.

TECHNICAL FIELD

The invention relates to a method for constructing a railway track. The invention relates in particular to a method for constructing a ballastless railway track.

BACKGROUND

A ballastless railway track, also known as “slabtrack”, is known in the state of the art and refers to a railway track in which the rails are typically attached directly to a concrete bedding or concrete ground and are not mounted on sleepers in ballast, which is often the case in conventional railways. A train, a tram or a metro can for example drive on such ballastless railway track.

Ballastless railways offer many advantages compared to conventional railways. They aim for example at a correct positioning of each element that is part of the railway, such as the rails and the concrete bedding, in which the geometric parameters remain almost unchanged in time. Furthermore, they require less maintenance than conventional railways, as a result of which, as less interventions are needed, the operational availability of the railway infrastructure is increased simultaneously.

The criteria for the construction of such ballastless railways are however often more demanding than for a conventional railway, as they require a larger precision as to the alignment and the position of the rails.

Methods for the construction of ballastless railways are known in the state of the art. EP 1 323 866 for example describes a method for the construction of a fixed railway, in which the railway-forming rails are first temporarily attached on both sides of a fixed basis on which a concrete bedding will be formed. Rail attachment elements are installed in the concrete bedding before it has hardened and are positioned precisely by means of a positioning mechanism, which positioning mechanism is guided by the temporarily installed rails. EP 1 460 174 describes a similar method in which the track bearing rails are temporarily fixed by means of width- and height-adjustable rail bearers, so that they can guide the positioning mechanism.

A problem with the current methods for the construction of ballastless railways is that they often require external positioning mechanisms for precisely positioning the permanent rail attachment means before concrete can be placed. These positioning mechanisms are often heavy and hard to work with, especially when rails have to be constructed in places that are difficult to reach or where there is little space such as for example in a tunnel, underground or on a bridge, as a result of which the installation of the rail attachment elements as well as the rails is often very slow. Furthermore, they are generally expensive in use and maintenance and they typically require specialized staff to operate them. Another problem of the methods according to the state of the art is that the finishing and the horizontal and vertical alignment of the concrete bedding often leave much to desire, and last long because it is mostly realized manually. As mentioned above, the correction of possible finishing errors at the concrete bedding is often very expensive and increases the cost of the construction of the railway significantly. Furthermore, the concrete can only be placed after positioning the rail attachment means. This is a time-consuming factor, as the concrete still must harden afterwards.

The present invention aims to find a solution for at least some of the above-mentioned problems.

There is a need for an improved method for the construction of ballastless railways, in which the concrete bedding can be provided in a correct, well-aligned manner and this in a fast, cost-efficient way with a good finishing. Furthermore, there is a need for a method in which the rails can be attached to and positioned on the concrete bedding on the correction position in a simple way, preferably without the use of external positioning mechanisms or without the need to adjust the positioning of the rails much afterwards.

SUMMARY OF THE INVENTION

In a first aspect, the invention relates to a method for the construction of a railway as described in claim 1.

The method according to the present invention allows to place a concrete bedding of a railway in a correct, well-aligned way and this in a fast, cost-efficient way with a good finishing, regardless of the location where the concrete bedding must be placed. The method according to the present invention preferably also allows rails to be attached to the concrete bedding in a simple way and this in the correct position on the concrete bedding, preferably without the use of external positioning mechanisms for the rail attachment means, or without the need to adjust the positioning of the rails much afterwards.

DESCRIPTION OF THE FIGURES

FIG. 1 provides a schematic description of a number of steps (A-I) of a method for the construction of a railway according to a preferred embodiment of the present invention.

FIG. 2 provides a schematic description of temporary attachment means that can be used for the temporary attachment of a rail and a casing in a trench according to an embodiment of the present invention.

FIG. 3 provides a schematic description of a number of steps (A-C) of a method for the construction of a railway according to an alternative embodiment of the present invention.

DETAILED DESCRIPTION

Unless otherwise specified, all terms used in the description of the invention, including technical and scientific terms, shall have the meaning as they are generally understood by the worker in the technical field of the invention. For a better understanding of the description of the invention, the following terms are explained specifically.

“A”, “an” and “the” refer in the document to both the singular and the plural form unless clearly understood differently in the context. “A dowel” means for example one or more than one dowel.

When “approximately” or “about” are used in the document together with a measurable quantity, a parameter, a period or moment, etc., variations of +/−20% or less, preferably +/−10% or less, more preferably +/−5% or less, still more preferably +/−1% or less, and even still more preferably +/−0.1% or less than and of the cited value are meant, as far as such variations apply to the invention that is described. It will however be clearly understood that the value of the quantity at which the term “approximately” or “about” is used, is itself specified.

The terms “include”, “including”, “consist”, “consisting”, “provide with”, “contain”, “containing”, “comprise”, “comprising” are synonyms and are inclusive of open terms that indicate the presence of what follows, and that do not exclude or prevent the presence of other components, characteristics, elements, members, steps, known from or described in the state of the art.

The citation of numeric intervals by means of end points includes all integers, fractions and/or real numbers between the end points, including these end points.

In a first aspect, the present invention relates to a method for the construction of a railway, preferably a ballastless railway. The method is appropriate for the construction of a railway, preferably a ballastless railway, in any place or location. The method is preferably appropriate for the construction of a railway at locations where there is little space and/or that are difficult to reach, such as in a tunnel, on a bridge, aqueduct or viaduct, underground, but as well in dense or desolate places, such as for example a desert, tundra or jungle. The method preferably relates to a method for the construction of a ballastless railway. This ballastless railway can include any ballastless railway and includes for example tram lines, underground lines, train lines or high-speed train lines.

The method according to the present invention includes the following steps:

-   -   a. the provision of a first concrete layer on a ground, which         first concrete layer includes a lower surface that is in contact         with the ground and an opposite upper surface;     -   b. the removal of at least a part of an upper part of the first         concrete layer, which upper part extends from the upper surface         of the concrete layer to the lower surface;     -   c. the provision of two temporary rails on the first concrete         layer of which at least a part of the upper part has been         removed;     -   d. the provision of concrete on the first concrete layer by         means of a vehicle that drives on the temporary rails, as a         result of which a second concrete layer is formed on the first         concrete layer;     -   e. the displacement of the temporary rails from the first         concrete layer to the second concrete layer, in which the rails         are attached permanently to the second concrete layer by means         of permanent attachment means.

When a concrete layer is placed on a ground, it often happens that the ground does not correspond perfectly with e.g. a horizontal x-y plane, but forms a particular angle and/or it happens that the ground shows irregularities, i.e. the ground is not perfectly flat, but show at particular places e.g. valleys or wells and at other places e.g. bulges or accumulations. As a result, the concrete layer that is placed on this ground, is often equally inclined and/or has the same irregularities as the ground. Moreover, extra irregularities can be created during the installation of the concrete layer. This causes the horizontal and vertical alignment of the first concrete layer, i.e. its upper surface on which the railway will be constructed, in most cases not to correspond with the planned horizontal and vertical alignment of the railway to construct. To solve this problem, in the method according to the present invention, a planned horizontal and vertical alignment of the railway to construct, is measured, taking into account the horizontal and vertical alignment of the first concrete layer, i.e. of the upper surface of the first concrete layer, in which the at least partially to be removed upper part of the first concrete layer is adjusted according to the planned alignment so that at least a part of the upper surface of the first concrete layer corresponds to the planned alignment. On at least a part of the upper surface, the inclination of the upper surface can for example be adjusted, so that it corresponds e.g. substantially with a planned inclination of the railway to construct, and/or at least a part of the upper surface can for example be levelled, so that the irregularities that are present on the upper surface, can be eliminated. Obviously, the horizontal and vertical alignment can be realized on a first concrete layer provided according to the method of the state of the art as well as on an existing concrete layer.

The temporary rails that are installed on the first concrete layer, of which at least a part of the upper part is removed, will according to the present invention preferably have the same adjusted horizontal and vertical alignment of the at least partially adjusted upper surface of the first concrete layer, i.e. the temporary rails will preferably be positioned on the first concrete layer where the upper surface is adjusted according to the planned alignment of the railway to construct. When placing the second concrete layer on the first concrete layer, the second concrete layer will also take the correct planned horizontal and vertical alignment because it has been installed by means of a vehicle driving on the temporary rails. In this way, by simply removing at least a part of the upper part of the first concrete layer, the second concrete layer can be placed in a correct, well-aligned way and this in a fast, cost-efficient way. Furthermore, the method according to the present invention has the advantage that the temporary rails, used for the construction of the first concrete layer, can also be used to form the final permanent rails on the second concrete layer, which makes the logistic aspect easier and requires less personnel, thus improving the cost-efficiency of the process. It is for example also possible to have a tired vehicle drive on the first concrete layer, of which at least a part of the upper part has been removed, so as to install the second concrete layer. This option also allows a correct, good alignment of the second concrete layer in a fast and cost-efficient way. In case of this option, in which a tired vehicle is used, the temporary rails are not necessary.

The provision of concrete on the first concrete layer by means of a vehicle that drives on the temporary rails, in which a second concrete layer is formed on the first concrete layer, can be realized next to or between two temporary rails. According to a preferred embodiment, the provision of concrete on the first concrete layer in step d) is realized between the two temporary rails, since this is practically easier, especially in places where the space is limited and/or that are difficult to reach.

The first concrete layer preferably has a concrete thickness measured between the upper surface and the lower surface along a z axis that is substantially perpendicular to a horizontal x-y plane. The upper part of the first concrete layer preferably extends from the upper surface of the concrete layer to the lower surface to a maximum of 99% of the concrete thickness, preferably to a maximum of 90% of the concrete thickness, more preferably to a maximum of 80% of the concrete thickness, still more preferably to a maximum of 60% of the concrete thickness, still more preferably to a maximum of 40% of the concrete thickness, still more preferably to a maximum of 30% of the concrete thickness, still more preferably to a maximum of 20% of the concrete thickness, most preferably to a maximum of 10% of the concrete thickness. According to a preferred embodiment, the upper part of the first concrete layer extends from the upper surface of the concrete layer to the lower surface to a maximum of 5% of the concrete thickness. In this way, the upper surface of the first concrete layer can be corrected and adjusted by means of the planned horizontal and vertical alignment of the railway to construct, without the need of removing considerably much of the first concrete layer, which again improves the cost-efficiency of the process.

According to an embodiment of the present invention, substantially the complete upper surface of the first concrete layer will be adjusted so that it corresponds to the planned alignment. The plane and/or the inclination of substantially the complete upper surface can for example be adjusted, so that it corresponds e.g. substantially with a planned plane and/or inclination of the railway to construct, and/or substantially the complete upper surface can for example be levelled, so that the irregularities that are present on the upper surface, can be eliminated. The temporary rails will thus, when providing on the first concrete layer, have the same horizontal and vertical alignment of the adjusted upper surface of the first concrete layer and thus also the second concrete layer, which is placed on the first concrete layer.

According to a particular preferred embodiment, only a part of the complete upper surface of the first concrete layer will be adjusted so that it corresponds to the planned alignment. Preferably, the removal of at least a part of the upper part of the first concrete layer is realized in step b) by providing at least two trenches in the first concrete layer that are substantially parallel to each other, preferably in which the two temporary rails are provided in the trenches, preferably one temporary rail per trench. Each trench hereby preferably has a trench depth measured from the upper surface of the concrete layer to the lower surface along a z axis, which z axis is substantially perpendicular to a horizontal x-y plane, in which the trench depth of each trench is adjusted according to the planned alignment of the railway to construct. In a preferred embodiment, each trench has a trench depth measured along the z axis extending from the upper surface of the concrete layer to the lower surface to a maximum of 99% of the concrete thickness, more preferably to a maximum of 80% of the concrete thickness, more preferably to a maximum of 60% of the concrete thickness, still more preferably to a maximum of 40% of the concrete thickness, still more preferably to a maximum of 30% of the concrete thickness, still more preferably to a maximum of 20% of the concrete thickness, most preferably to a maximum of 10% of the concrete thickness. According to a preferred embodiment, each trench has a trench depth measured along the z axis extending from the upper surface of the concrete layer to the lower surface to a maximum of 5% of the concrete thickness. In this way, the trench depth of each trench can be corrected and adjusted by means of the planned alignment of the railway to construct, without the need of removing considerably much of the first concrete layer. The trench depth according to the present invention has preferably a value varying between about 0.1 cm and about 10 cm, more preferably between about 0.2 cm and about 8 cm, still more preferably between about 0.3 and about 6 cm, still more preferably between about 0.4 cm and about 4 cm, most preferably between about 0.5 cm and 2 cm. Preferably, the adjustment of the trench depth, as well as the orientation of each trench in the horizontal x-y plan, will be adjusted according to the planned alignment of the railway to construct.

Each trench preferably has a trench length and a trench width, in which the trenches extend substantially parallel to each other according to their trench length, which is preferably essentially endless. The trench width of each trench is preferably sufficiently wide to position at least one temporary rail into, in which the rail extends in its length according to the trench length. Each trench preferably has a trench depth with a value varying between about 5 cm and about 200 cm, more preferably between about 10 cm and about 150 cm, still more preferably between about 15 and about 100 cm, still more preferably between 20 cm and about 80 cm, most preferably between about 25 cm and 60 cm.

The mutual distance between the two trenches, as measured according to a transverse direction substantially perpendicular to the longitudinal direction, in which longitudinal direction the two trenches extend substantially parallel to each other, is preferably wider than the width of the two concrete layers to place measured according to the transverse direction, so that the second concrete layer can be placed between the two trenches. The mutual distance between the two trenches, as measured according to the transverse direction, preferably has a value between about 0.5 m and about 7 m, still more preferably between about 1 m and about 6 m, still more preferably between about 1.5 m and about 5 m, still more preferably between 2 and 4 m, most preferably a value of about 3 m, in which the mutual distance is measured from substantially the middle of the trench width of the one trench to substantially the middle of the trench width of the other trench according to the transverse direction.

Because the alignment of the trenches is adjusted according to the planned alignment of the railway to construct, as the two temporary rails are preferably provided in the trenches, the rails will also take the same adjusted alignment and thus also the second concrete layer that is placed on the first concrete layer by means of a vehicle driving on the temporary rails.

The removal of at least a part of the upper part of the first concrete layer can be realized in any way. According to a preferred embodiment of the present invention, the removal of at least a part of the upper part of the first concrete layer is realized by milling away that part e.g. by means of a device appropriate for milling or milling device. The present milling devices are able to remove in a very precise way at least a part of the upper part of a concrete layer and preferably allow to correspond at least a part of the upper part of the first concrete layer up to 1 mm precisely with the planned alignment of the railway to construct.

According to a preferred embodiment, for providing concrete in step d), a casing is made on the first concrete layer, in which casing the concrete will be provided. The term “casing” according to the present invention is a term known in the state of the art and refers to an often temporarily provided mould or counter mould in which concrete can be provided, e.g. poured. The mould or counter mould hereby holds the concrete and optionally also a reinforcement for concrete in its place during the provision and hardening of the concrete. The mould or counter mould can contain any material known in the state of the art such as for example wood, plastic, metal, steel or any other combination of these materials. When the concrete has hardened, the casing is commonly removed and optionally reused. In places where the casing holds the concrete in its place during its hardening, an additional coating or layer can be provided allowing the mould or counter mould to be removed more easily from the concrete, once it has hardened.

The use of a casing for the second concrete layer allows, next to a correct alignment of the second concrete layer, to obtain also a better finishing, especially at the edges or the second concrete layer. The casing can be positioned next to or between the two temporary rails. The casing is preferably positioned between the two temporary rails so that concrete can be provided easily by means of a vehicle that drives on the temporary rails, especially in places where there is little space and/or that are difficult to reach. The casing will preferably be positioned on the first concrete layer, where the upper surface is adjusted according to the planned alignment of the railway to construct, so that the casing will also take this alignment and thus also the second concrete layer, that is formed by means of the casing. In another preferred embodiment, the casing is inclined in a certain angle with respect to the first concrete layer. This can be desirable when another alignment is desired at least locally for the second concrete layer than for the first concrete layer.

When substantially the whole upper surface of the first concrete layer is adjusted so that it corresponds to the planned alignment of the railway to construct, the casing, positioned on the first concrete layer, will have the same adjusted horizontal and vertical alignment of the adjusted upper surface of the first concrete layer and thus also the second concrete layer, that is provided on the first concrete layer.

When only a part of the upper surface of the first concrete layer is adjusted so that it corresponds to the planned alignment of the railway to construct, the casing will preferably take the same adjusted horizontal and vertical alignment of the adjusted upper surface of the first concrete layer, i.e. the casing will preferably be positioned on the first concrete layer where the upper surface is adjusted according to the planned alignment of the railway to construct, so that also the second concrete layer, formed with the casing, will take this alignment. When according to a preferred embodiment, at least two trenches are provided in the first concrete layer, as described above, the casing will preferably be positioned in the two trenches, between the two temporary rails, in which casing the concrete will be provided. It is however also possible that for example two extra trenches are provided between the two trenches that were already provided with the temporary rails, in which two extra trenches the casing is provided, in which the extra two trenches extend in parallel to each other and to the two trenches already provided, and in which the extra two trenches, just like the two trenches already provided, have an alignment that is adjusted according to the planned alignment of the railway to construct. Furthermore, it is also possible that not the two temporary rails are positioned in the two trenches, but the casing, in which the two temporary rails are preferably positioned on both sides next to the two trenches, so that, thanks to the correct alignment of the casing in the trenches, the second concrete layer also has the correct alignment, when concrete is poured in by means of a vehicle driving on the two temporary rails. It will be clear that different combinations or variations are possible.

The two temporary rails can be provided separately on the first concrete layer or they can be attached temporarily to the first concrete layer with temporary attachment means. According to a preferred embodiment, the provision of the two temporary rails on the first concrete layer is realized by attaching the temporary rails to the first concrete layer by means of temporary attachment means. This avoids that when a vehicle is driving on the temporary rails when pouring the concrete, the rails can for example turn over or displace, which would also have an effect on the installation of the second concrete layer.

According to a preferred embodiment, the casing contains at least two substantially plate-shaped casing elements, forming a gutter with the first concrete layer in which the concrete is provided. The at least two substantially plate-shaped casing elements preferably form a gutter with the upper surface of the first concrete layer. When according to an embodiment, two trenches are provided in the first concrete layer, as described above, the two casing elements are preferably positioned in the two trenches, one casing element per trench, between the two temporary rails. When two extra trenches are provided between the two trenches already provided with the temporary rails, as described above, the two casing elements are preferably positioned in the two extra trenches, one casing element per extra trench. Furthermore, it is also possible that the two casing elements are positioned in the two trenches, one casing element per trench, and not the temporary rails, in which the two temporary rails are preferably positioned on both sides next to the two trenches. It will be clear that different combinations or variations are possible.

The casing can be provided on the first concrete layer by means of any attachment means known in the state of the art. According to an embodiment, the casing will be attached to the first concrete layer by means of temporary attachment means, so that the casing will not turn over or displace in use, but can still be easily removed from the first concrete layer after use. According to a preferred embodiment, the casing is removed after the provision of the second concrete layer and can preferably be reused. This allows to systematically use the same casing during the construction of the railway.

According to a preferred embodiment, for the provision of the concrete in step d), a reinforcement is installed, which reinforcement is appropriate for reinforcing the second concrete layer. The term “reinforcement” or “reinforcement for concrete”, as used here as synonyms, is a term known in the state of the art and refers to a reinforcing element that is provided in concrete for reinforcing it and making it more resistant to for example compressive or tensile forces to which the concrete is subjected. When a reinforcement is present in the concrete, the term “reinforced concrete” is typically used. The reinforcement according to the present invention can contain any configuration known in the state of the art and can for example be provided in the form of rods, nets, cables, grids, etc. and can further contain any material known in the state of the art, such as metal, e.g. steel, optic fibre, plastic, etc. According to a preferred embodiment, the reinforcement preferably contains rods, preferably steel rods. The reinforcement can be provided on the first concrete layer without a casing or it can also be provided on the first concrete layer combined with a casing, whether or not connected (bearingly) thereto. According to a preferred embodiment, a casing as well as a reinforcement is provided, in which the reinforcement is preferably connected bearingly to the casing. More preferably, the reinforcement is connected demountably with the casing, allowing the casing to be disassembled from the reinforcement after use, so that the casing can be reused and the reinforcement stays behind in the second concrete layer.

According to a preferred embodiment, at least a part of the permanent attachment means for the permanent attachment of the rails to the second concrete layer, are connected bearingly to the reinforcement. The permanent attachment means according to the present invention can include any attachment means known in the state of the art for attaching rails to a concrete layer. WO 2014 198 585, WO 2014 184 059 and WO 2009 043 822 give non-limiting examples of attachment means that can be used according to the present invention and are hereby included by reference. The attachment means can for example include at least one screw, plate, spring element, dowel, etc. in any form, configuration or material. When in the present invention, it is said that the reinforcement is connected bearingly to at least a part of the permanent attachment means, it means that the reinforcement can be connected bearingly to any part of the permanent attachment means, such as for example to a screw, a plate, a spring element, a dowel, etc. of the permanent attachment means or any combination of the parts of the permanent attachment means, such as for example a combination of a dowel and a screw.

The bearing connection of the reinforcement to at least a part of the permanent attachment means allows to provide that part of the attachment means automatically with the reinforcement. This allows to position that part of the permanent attachment means in such way in the reinforcement that, once concrete is provided over the reinforcement and the second concrete layer is formed, the rails can be mounted in a correct, i.e. a desired position to the second concrete layer by means of the at least partially prepositioned attachment means. The reinforcement preferably has a correct alignment corresponding to the planned alignment of the railway to construct, for example because the reinforcement is positioned on the upper surface of the first concrete layer where the upper surface is adjusted to the planned alignment, e.g. when substantially the complete upper surface of the first concrete layer is adjusted so that it corresponds to the planned alignment, or because the reinforcement is connected to the casing, e.g. connected bearingly or demountably, in which the casing is positioned on the at least partially adjusted upper surface of the first concrete layer so that, by means of the correct alignment of the casing, the reinforcement connected to the casing also has a correct alignment. By means of the correct alignment of the reinforcement, at least a part of the permanent fixation means, connected bearingly to the reinforcement, will also be aligned correctly. With other words, by the simple step of removing at least a part of the upper part of the first concrete layer, all elements whether or not connected mutually, i.e. the temporary rails, casing and/or at least a part of the permanent attachment means, can take the correct planned alignment, so that the resulting second concrete layer can be installed in a correct, well aligned way on the first concrete layer.

According to an embodiment of the present invention, substantially the complete upper surface of the first concrete layer will be adjusted so that it corresponds to the planned alignment, in which the two temporary rails, a reinforcement and optionally a casing are provided on the first concrete layer. The temporary rails, the reinforcement and optionally the casing will thus, at the provision on the first concrete layer, have the same horizontal and vertical alignment as the adjusted upper surface of the first concrete layer and thus also the second concrete layer, which is placed on the first concrete layer. At least a part of the permanent attachment means for the permanent attachment of the rails to the second concrete layer can hereby be connected bearingly to the reinforcement, as described above.

According to a preferred embodiment, at least a part of the permanent fixation means for the permanent fixation of the rails to the second concrete layer, is connected bearingly to the reinforcement and the reinforcement is connected bearingly to the casing, more preferably connected demountably to the casing. Because the casing is preferably positioned on the at least partially adjusted upper surface of the first concrete layer with an alignment corresponding to the planned alignment of the railway to construct, as the reinforcement is connected bearingly to the casing, the reinforcement will have a same corresponding alignment, as well as at least a part of the permanent attachment means that are connected bearingly to the reinforcement. With other words, by providing the casing, at least a part of the permanent attachment means will also automatically be provided with a correct alignment and at already a correct position on the reinforcement where the rails will later be attached to the second concrete layer. When concrete is poured in the casing, that part of the permanent attachment means will be surrounded and fixed already at the correct position in the concrete and thus already be provided in the second concrete layer, so that when the rails have to be attached to the second concrete layer afterwards, the rails can simply be displaced to this position and can be fixed using the permanent attachment means. This ensures that no external, heavy positioning mechanisms which are hard to work with, are required anymore to correctly position the attachment means in the second concrete layer, which is now often the case in methods according to the state of the art.

According to a preferred embodiment, the permanent attachment means include at least one dowel, in which the reinforcement is connected bearingly to the at least one dowel. A “dowel” as used here, is a term known in the state of the art and refers to a anchoring element that is typically used for the anchoring of an object, typically a screw, in a non-elastic material, such as for example concrete. The dowel is hereby typically placed in a precisely fitting preformed hole in the non-elastic material or can be placed in the non-elastic material when this material is in another state. For example in the case of concrete, the dowel can be surrounded by concrete in a fluid state or it can be placed in the concrete when it is still in a fluid state, after which the concrete is hardened and the dowel is fixed in the concrete. The dowel can include any form as well as any material known in the state of the art. The dowel preferably contains a plastic material that is preferably elastic or at least partially elastic. The dowel is preferably hollow and substantially tubular-shaped with an open end and an opposite closed end. To realize an anchoring, the screw is typically inserted via the open end in the hole of the dowel. The inner surface of the tubular-shaped dowel is hereby typically provided with a screw pattern that is complementary to the screw pattern of the screw that is inserted in the dowel, so that the screw is inserted in the dowel by means of a turning movement and thus gets fixed in the dowel. Dowels with two open ends can for example also be used instead of the said dowel with an open and a closed end. A dowel with two open ends has the advantage that a liquid, such as for example water, cannot accumulate in the dowel, and can be used for drainage.

The preferably bearing connection between the reinforcement and the at least one dowel, allows this dowel to already be positioned correctly on the reinforcement even before the concrete is provided. In this way, when providing the concrete, the at least one dowel can be surrounded by concrete and can be anchored in the second concrete layer and this already in the correct position where afterwards, after the installation of the second concrete layer, the rails can be provided and attached to the second concrete layer. The permanent attachment means preferably contain at least one screw that fits in the dowel. This screw is preferably only placed in the dowel when the second concrete layer is already provided and hardened. In this way, the rails can be attached to the second concrete layer by means of the screw by placing the screw in the prepositioned dowel in the second concrete layer. Furthermore, the permanent attachment means preferably contain, next to at least one screw, at least one spring element and at least one fixation plate for further positioning and fixing the rails on the second concrete layer.

The reinforcement is preferably connected bearingly to the at least one dowel via at least one positioning element, i.e. an element that holds the dowel in the correct position on the reinforcement. The at least one positioning element preferably holds the dowel positioned with the closed end of the dowel substantially oriented to the upper surface of the first concrete layer. The latter applies to a dowel with a closed end and an open end, as described above. With a dowel with two open ends, one open end of the dowel will be oriented substantially to the upper surface of the first concrete layer. The positioning element can for example contain a clamp system, which clamps the dowel and thus holds it in position or it can for example contain a annular holder that encloses the outer diameter of the dowel and thus holds the dowel in position. The positioning element can be an integral part of the reinforcement or it can be connected separately to the reinforcement. The positioning element, holding the dowel in place, can optionally be placed in different adjustable positions on the reinforcement in order to adjust the position of the dowel to the reinforcement. Furthermore, the dowel and/or the positioning element can contain a control mechanism, that checks if the dowel is held in the correct position via the positioning element. The dowel and/or positioning element can for example contain a magnet that allows to position the dowel and the positioning element in a correct mutual position.

According to a preferred embodiment, the permanent attachment means include at least one dowel, in which the reinforcement is connected bearingly to the at least one dowel, preferably by means of at least one positioning element, and the reinforcement is connected bearingly to the casing, more preferably connected demountably to the casing. The casing preferably hereby contains at least two substantially plate-shaped casing elements, that can be positioned on the first concrete layer according to any configuration as described above, that form an upwardly open, gutter-shaped construction with the first concrete layer, and between which casing elements the reinforcement is enclosed. The positioning element preferably holds the dowel in such position between the two casing elements of the casing so that the at least one dowel is located already in the correct position between the two casing elements where afterwards, after forming the second concrete layer, the rails can be provided and attached to the second concrete layer.

According to another embodiment of the present invention, at least a part of the attachment means for permanently attaching the rails to the second concrete layer, are placed in the second concrete layer before substantially hardening of the second concrete layer. According to a preferred embodiment, the permanent attachment means include at least one dowel that is placed in the second concrete layer before substantially hardening of the second concrete layer. For correctly positioning at least a part of the attachment means in the second concrete layer, positioning mechanisms are preferably used as known in the state of the art.

According to still another embodiment of the present invention, at least a part of the attachment means for permanently attaching the rails are placed in the second concrete layer after substantially hardening of the second layer. According to a preferred embodiment, the permanent attachment means include at least one dowel that is placed in the second concrete layer after substantially hardening of the second concrete layer, preferably in a precise fitting preformed hole in the second concrete layer. Any technique known in the state of the art can be used for providing at least a part of the fixation means in the second concrete layer after substantially hardening of the second concrete layer.

According to a preferred embodiment, the first concrete layer contains at least one connection element ensuring a better fixation between the first concrete layer and the second concrete layer. Such connection element can for example be an element that is partially embedded in the first concrete layer and that is partially protruding through the upper surface of the first concrete layer. When providing concrete on the first concrete layer for forming the second concrete layer, the part of the connection element protruding through the first concrete layer, will be poured over and embedded with concrete and thus form a connection between the first and the second concrete layer. The connection element can contain any material such as metal, e.g. steel, optic fibre, plastic, etc. and can take any form or configuration, such as in the form of rods, nets, cables, grids, etc. According to a preferred embodiment, the connection element is rod-shaped and preferably contains steel.

The concrete according to the present invention can contain any type of concrete and can contain any composition as known in the state of the art. The type of concrete and concrete composition of the first concrete layer can, but doesn't have to, be equal to the type of concrete and the concrete composition of the second concrete layer.

In the following, the invention will be described by means of non-limiting examples illustrating the invention with reference to the figures. These examples are not limiting and cannot be interpreted as limiting the scope of the invention.

FIG. 1 provides a schematic description of the different steps (A-H) of a method for the construction of a railway according to a preferred embodiment of the present invention. It relates hereby to a method for the construction of a railway in a tunnel, where the lack of space often make it difficult to construct a railway in an easy and cost-efficient way. The figure hereby illustrates that two railways are constructed next to each other in a tunnel (FIG. 1A). It will however be clear that the method can also be used for the construction of one or more railways, whether or not in a tunnel.

FIG. 1A shows a cross-section of a tunnel (1). After drilling the tunnel (1), a filling material is placed on the bottom of the tunnel for forming a ground (2), onto which a first concrete layer (3) is installed. In the first concrete layer, connection elements (5) are placed, two per railway to construct. These connection elements (5) will ensure a better fixation between the first concrete layer (3) and the second concrete layer to install (see further description).

FIG. 1B shows an enlarged image of the region indicated on FIG. 1A (rectangle). Hereby, the ground (2) is again visible with on top of it the first concrete layer (3) with the connection elements (5). As shown in FIG. 1B, these connection elements are partially embedded in the first concrete layer (indicated with a dotted line) and they protrude on two places (per connection element) above the first concrete layer (3). The first concrete layer (3) has a lower surface (L) that is in contact with the ground (2) and an upper surface (U) opposite to the lower surface. Part of an upper part of the first concrete layer is removed in the shape of two trenches (4) that extend substantially parallel to each other, in which each trench has a trench depth (Z₄) measured according to a z axis substantially perpendicular to a horizontal x-y plane extending from the upper surface (U) of the concrete layer to the lower surface (L) with a concrete thickness (Z₄) up to 5%, in which the trench depth (Z₄) of each trench is adjusted according to the planned alignment of the railway to construct. The orientation of each trench in the horizontal x-y plan is hereby also adjusted according to the planned alignment of the railway to construct. Each trench has a trench length (not shown) and a trench width (according to the y axis). The trench width according to the present embodiment includes a value of about 25 cm and the trench depth (Z₄) a value of about 1 cm. The two trenches (4) extend substantially parallel to each other according to their trench length that is essentially endless and extends equally with the longitudinal direction of the railway to construct. The trenches are made by means of a milling device.

As shown in FIG. 1C, in the next step, two temporary rails (6) are provided in the trenches (4), one temporary rail (6) per trench (4), in which the temporary rails extend in its length according to the trench length of the trenches (not shown). These temporary rails can be placed loose in the trenches or temporarily attached in the trenches to the first concrete layer (3) by means of temporary attachment means (see FIG. 2). Next to the temporary rails (6), preferably positioned between the two temporary rails (6), two plate-shaped casing elements (7) are provided in the trenches (4), i.e. one casing element per trench. The casing element can hereby be positioned right along the temporary rails as shown in FIG. 1C, or the casing element and the temporary rail can be positioned at a particular distance in the trench from each other (not shown). The two casing elements (7) form an upwardly open, gutter-shaped construction with the first concrete layer (3) in which concrete can be provided. Because the trenches are adjusted to have an alignment that corresponds with the alignment of the railway to construct, the temporary rails and the casing, provided in the trenches, will have one same alignment.

The temporary rails (6) can be placed loose in the trenches as shown schematically in FIG. 1 or temporarily attached in the trenches to the first concrete layer (3) by means of temporary attachment means as shown schematically in FIG. 2. FIG. 2 shows, similar to FIG. 1, the first concrete layer (3), with a trench (4) provided therein, in which the temporary rail (6) is attached temporarily to the first concrete layer (3) in the trench (4) by means of a temporary attachment means that includes two screws (17) that are temporarily attached in the first concrete layer (3) in the trench (4). The temporary attachment means further include an attachment plate (16) that is positioned in the trench and is fixed to the first concrete layer by means of the two screws (17). Two spring elements (18) that hold the temporary rail (6) in position on the attachment plate are connected bearingly with the screws (17) and the attachment plate (16). The attachment plate (16) will position the temporary rail as such in the trench that the rail has the same alignment as the trench, which is adjusted to have an alignment that corresponds to the alignment of the railway to construct. Next to the anchoring plate (16) clamped between the side wall of the trench (4) and the attachment plate (16), a casing element (7) is provided that will also have the same alignment as the alignment of the trench.

Simultaneously with or after the positioning of the temporary rails (6) and the casing elements (7), a steel reinforcement (8) is provided between the two casing elements (7), which reinforcement is connected demountably to the casing elements by means of screws (10) (FIG. 1D and FIG. 2). The reinforcement (8) includes according to the present embodiment steel rods (8) with prepositioned dowels (9) (FIG. 1D). The dowels (9) are an integral part of the permanent attachment means that will attach the rails (6) later onto the second concrete layer to install. The dowels are positioned on the reinforcement via annular positioning elements (not shown) and are hollow and substantially tubular-shaped with an open end and an opposite closed and, in which the closed end of each dowel is oriented substantially to the upper surface of the first concrete layer. Dowels with two open ends can for example also be used instead of the said dowels with an open and a closed end. A dowel with two open ends has the advantage that a liquid, such as for example water, cannot accumulate in the dowel, and can be used for drainage.

After providing the steel reinforcement (8) with prepositioned dowels (9), concrete is provided between the two casing elements (7) by means of a railway vehicle (12) that drives with its wheels and/or caterpillars (13) over the temporarily installed rails (6) (FIG. 1E), for forming a second concrete layer (11) onto the first concrete layer (3). Optionally, a device for levelling the provided concrete, as for example a vibrated needle or a vibrated bar, can be used to level the concrete equally in the casing and to push onto it in order to obtain a beautiful, smooth second concrete layer. After the partial or complete hardening of the concrete (11), the two casing elements are disassembled from the reinforcement (8) that is now embedded in the second concrete layer (11) (FIG. 1F). The casing elements can preferably be reused. Subsequently, the surface of the second concrete layer is milled smoothly to exactly where the open end of the dowels (9) is positioned (FIG. 1G). In a next step, the temporary rails (6) are displaced from the trenches (4) to the position of the dowels (9) and attached there by means of permanent attachment means (14) via the dowels (9) (FIG. 1H). Optionally, the trenches (4) in the first concrete layer at both sides of the second layer can be milled before or after the permanent attachment of the rails to the second concrete layer, so that a smooth, even first concrete layer is obtained (FIG. 11).

FIG. 3 A-C shows a schematic illustration of a number of steps of the method according to another embodiment of the present invention. FIG. 3A shows, similar to FIG. 1, a cross-section of a ground (2) onto which a first concrete layer (3) is provided. Here too, connection elements (5) are provided for a better attachment between the first concrete layer (3) and the second concrete layer to install. According to this embodiment, a part of the upper part of the first concrete layer is again removed in the form of two trenches (4B). In this embodiment, the two extra trenches (4A) are provided between the two trenches (4B). The outer two trenches (4B) are appropriate to place temporary rails (6) into, while the inner two extra trenches (4A) are appropriate to place two casing elements (7) into, as shown in FIG. 3B. Both the outer two trenches (4B) and the inner two extra trenches (4A) extend hereby substantially in parallel to each other according to the longitudinal direction of the rail to construct and are adjusted to the planned alignment of the railway to construct. The trench width of the inner two extra trenches (4A) is hereby adjusted to correspond to the dimensions of the casing elements (7). Furthermore, a reinforcement (15) is provided between the two casing elements (7) in the form of two steel rods that mutually connect the two casing elements and in this way also hold the two casing elements in position. Subsequently, concrete is again poured between the two casing elements (7) by means of a railway vehicle that drives over the temporary rails (not shown), for forming a second concrete layer (11) onto the first concrete layer (3). According to this embodiment, no reinforcement is used with prepositioned dowels for correctly positioning the rails (6) onto the second concrete layer, but other mechanisms can also be used. The attachment means for the rails can for example be placed in the concrete before it is hardened, or, after hardening and optional milling of the concrete, the attachment means can be drilled and attached in the concrete to permanently attach the rails to the second concrete layer.

It will be understood that the present invention is not limited to the embodiments described above and that some adjustments or changes can be added to the described examples without changing the scope of the enclosed claims. 

1. Method for constructing a railway, which method includes the following steps: a. the provision of a first concrete layer (3) on a ground (2), which first concrete layer includes a lower surface that is in contact with the ground and an opposite upper surface; b. the removal of at least a part of an upper part of the first concrete layer, which upper part extends from the upper surface of the concrete layer to the lower surface; c. the provision of two temporary rails (6) on the first concrete layer of which at least a part of the upper part has been removed; d. the provision of concrete on the first concrete layer by means of a vehicle (12, 13) that drives on the temporary rails, as a result of which a second concrete layer (11) is formed on the first concrete layer; e. the displacement of the temporary rails from the first concrete layer to the second concrete layer, at which the rails are permanently attached to the second concrete layer by means of permanent attachment means (14), wherein a planned horizontal and vertical alignment of the railway to construct, is measured, taking into account the horizontal and vertical alignment of the first concrete layer, in which the at least partially to be removed upper part of the first concrete layer is adjusted according to the planned alignment so that at least a part of the upper surface of the first concrete layer corresponds to the planned alignment.
 2. Method of claim 1, in which the provision of concrete onto the first concrete layer in step d) is realized between the two temporary rails.
 3. Method of claim 1, wherein the removal of at least a part of the upper part of the first concrete layer in step b) is realized by providing at least two trenches in the first concrete layer that extend substantially in parallel to each other, preferably in which the two temporary rails are provided in said trenches.
 4. Method of claim 1, in which for the provision of concrete in step d), a casing is provided on the first concrete layer, in which casing the concrete will be provided and which casing is preferably positioned between the two temporary rails.
 5. Method of claim 3, in which for the provision of concrete in step d), a casing is provided, which casing is positioned in the two trenches between the two temporary rails and in which casing the concrete will be provided.
 6. Method of claim 4, in which the casing contains at least two substantially plate-shaped casing elements, forming a gutter with the first concrete layer in which the concrete is provided.
 7. Method of claim 4, in which the casing is attached on the first concrete layer by means of temporary attachment means.
 8. Method of claim 4, in which the casing is removed after the provision of the second concrete layer and can preferably be reused.
 9. Method of claim 1, in which for the provision of concrete in step d), a reinforcement is provided, which reinforcement is appropriate for reinforcing the second concrete layer and which reinforcement is preferably attached demountably to the casing, if present.
 10. Method of claim 9, in which at least a part of the permanent attachment means for the permanent attachment of the rails to the second concrete layer, are connected bearingly to said reinforcement.
 11. Method of claim 10, in which said permanent attachment means include at least one dowel and in which said reinforcement is connected bearingly to at least one dowel, preferably via at least one positioning element.
 12. Method of claim 1, in which at least a part of the attachment means for permanently attaching the rails to the second concrete layer, are placed in the second concrete layer before substantially hardening of the second concrete layer.
 13. Method of claim 9, in which at least a part of the attachment means for permanently attaching the rails are placed in the second concrete layer after substantially hardening of the second layer.
 14. Method of claim 1, in which the first concrete layer contains at least one connection element ensuring a better attachment between the first concrete layer and the second concrete layer.
 15. Method of claim 1, in which the provision of the two temporary rails is realized by attaching the temporary rails with temporary attachment means onto the first concrete layer. 